In surgical procedures it is frequently necessary to insert tubes for injecting contrast mediums into arteries, ducts, and veins preliminary to or as a part of the surgical procedure. In inserting these tubes, hemostats, forceps or other clamp-like structures must be utilized to grip the instrument adjacent the tip for insertion in the vein or duct. Additional steps in the surgical procedure frequently necessitate the closure of the duct around the instrument adjacent the tip. Leakage can occur in this area. Inadvertent induction of air into the procedures hampers the test such as air in the biliary tree can appear on x-rays as a gallstone.